This Supreme Court advocate and former solicitor general during the George W. Bush administration is one of the nation’s most influential lawyers. Olson is at the forefront of the court battle over marriage equality, an endeavor he began in 2009 when he and New York lawyer David Boies filed a lawsuit in California challenging the state’s same-sex-marriage ban. A prominent Republican, Olson says the issue isn’t one of politics but of human rights.

Last year, in recognition of their efforts, Time magazine named Olson and Boies to its list of the 100 most influential people worldwide. The pair convinced the California federal-court judge to strike down the same-sex-marriage ban as unconstitutional. The case is now on appeal.

Olson may be best known as the lawyer who ensured Bush the presidency by successfully arguing Bush v. Gore at the high court, but his advocacy for same-sex marriage is becoming an equally prominent part of his legacy.

He has argued 58 times at the Supreme Court, including two appearances before the justices last term.

Olson represented the NFL Players Association this summer during appellate proceedings over the player lockout that threatened to delay the start of the NFL season. He says he’s a Redskins fan, though it’s tough to imagine he has time for football.